My guess is that Java is becoming less popular because nobody wants to maintain someone else's legacy code. If you only admit to knowing a recent language you

My guess is that Java is becoming less popular because nobody wants to maintain someone else's legacy code. If you only admit to knowing a recent language you get to write your own new code in that language. Then eventually the new language will accumulate cruft (features) and become the old language and the same thing will happen again. It took a long time for FORTRAN to be replaced by C and C++ and for those languages to be partially replaced by Java. Java is being replaced in an even shorter time frame. It's part of the trend of scrapping the past rather than improving it and making it more stable. In some cases that is a good thing, in others it destroys things.